[PATCH AUTOSEL 5.5 19/67] RISC-V: Don't enable all interrupts in trap_init()

From: Sasha Levin
Date: Thu Mar 05 2020 - 12:23:55 EST


From: Anup Patel <anup.patel@xxxxxxx>

[ Upstream commit 6a1ce99dc4bde564e4a072936f9d41f4a439140e ]

Historically, we have been enabling all interrupts for each
HART in trap_init(). Ideally, we should only enable M-mode
interrupts for M-mode kernel and S-mode interrupts for S-mode
kernel in trap_init().

Currently, we get suprious S-mode interrupts on Kendryte K210
board running M-mode NO-MMU kernel because we are enabling all
interrupts in trap_init(). To fix this, we only enable software
and external interrupt in trap_init(). In future, trap_init()
will only enable software interrupt and PLIC driver will enable
external interrupt using CPU notifiers.

Fixes: a4c3733d32a7 ("riscv: abstract out CSR names for supervisor vs machine mode")
Signed-off-by: Anup Patel <anup.patel@xxxxxxx>
Reviewed-by: Atish Patra <atish.patra@xxxxxxx>
Tested-by: Palmer Dabbelt <palmerdabbelt@xxxxxxxxxx> [QMEU virt machine with SMP]
[Palmer: Move the Fixes up to a newer commit]
Reviewed-by: Palmer Dabbelt <palmerdabbelt@xxxxxxxxxx>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
arch/riscv/kernel/traps.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/riscv/kernel/traps.c b/arch/riscv/kernel/traps.c
index f4cad5163bf2c..ffb3d94bf0cc2 100644
--- a/arch/riscv/kernel/traps.c
+++ b/arch/riscv/kernel/traps.c
@@ -156,6 +156,6 @@ void __init trap_init(void)
csr_write(CSR_SCRATCH, 0);
/* Set the exception vector address */
csr_write(CSR_TVEC, &handle_exception);
- /* Enable all interrupts */
- csr_write(CSR_IE, -1);
+ /* Enable interrupts */
+ csr_write(CSR_IE, IE_SIE | IE_EIE);
}
--
2.20.1